Simulation of Active Control of Asymmetric Flows Around Slender Pointed Forebodies

At high angles of attack, the flowfield over slender forebodies becomes asymmetric with substantial side force, which may exceed the available control capability. The unsteady compressible Navier-Stokes equations are used to investigate the effectiveness of different active control methods to alleviate and possibly eliminate the flow asymmetry and the subsequent side force. Although the research work focuses on active control methods, a passive control method has been investigated. The implicit, Roe flux-difference splitting, finite volume scheme is used for the numerical computations. Both locally-conical and three-dimensional solutions of the Navier-Stokes equations are obtained. The asymmetric flow over five-degree semi-apex angle cone is used as a reference case to which the different control methods are applied and compared. For the passive control method, the side-strakes control is investigated. The parametric study includes the control effectiveness of the strake span length. For the active control methods, flow injection in the normal and tangential directions to the body surface has been investigated. Both uniform and pressure-sensitive mass flow injection are applied, and the effects of mass flow rate, injection angle and injection length have also been studied. Injection, with a parabolic profile, is applied from the cone sides tangent to its surface. Surface-heating, where temperature of the cone surface is increased, is also investigated. The effectiveness of a hybrid method of flow control which combines injection with surface heating has been studied. The cone spinning and rotary oscillation around its axis are applied as an active control method. The computational applications include the effects of uniform spinning rates and periodic rotary oscillations at different amplitudes and frequencies on the flow asymmetry

Sea Level Variation Along the Western Coast of the Arabian Gulf

Observed hourly tidal heights from six stations during the period 1980-1987 were used in the analyses. Daily readings of the pressure at mean sea level from three meteorological stations were also used. The variations of the observed daily mean sea level were studied at the six stations, giving low values in the winter season, and high ones in summer and spring seasons. The monthly mean sea level showed higher values during July and August and lower ones in the winter season. As the Arabian Gulf is generally considered a shallow sea, the meteorological conditions are the main cause of the sea level variation. This was shown by the variation of the daily mean sea level residual at the six stations. From the analyses of the coherence of several parameters, the pressure difference over the Gulf area did not give a noticeable effect with either the daily observed sea level or the daily sea level residual. Generally speaking, the important factor affecting the sea level variation in the Arabian Gulf is the pressure system covering the area either during the summer or the winter seasons

Utility of Certain Nucleophilic Aromatic Substitution Reactions for the Assay of Ethamsylate in its Dosage forms and in Presence of its Degradation Product

The study represents the first report on the development of spectrophotometric methods for determination of ethamsylate (EST) in the presence of hydroquinone as an impurity and/or acidic degradation product. The proposed methods are based on the reaction of EST through it,s secondary amino group either with 1,2-naphthoquinone-4-sulphonate sodium (NQS) at pH 10.7 or 2,4-dinitrofluorobenzene (DNFB) at pH 9.3 to form orange and yellow colored reaction products peaking at 478 and 387 nm for methods (I) and (II), respectively. The different experimental parameters affecting the development and stability of the reaction products in methods (I) and (II) were carefully studied and optimized. The absorbance-concentration plots were rectilinear over the concentration ranges of 2-30 and 2-14 µg mL−1 for methods (I) and (II), respectively. The lower detection limits were 0.13 and 0.19 µg mL−1 and the lower quantitation limits were 0.44 and 0.63 µg mL−1 for methods (I) and (II), respectively. Both methods were successfully applied to commercial ampoules and tablets

Micellar liquid chromatographic method for the simultaneous determination of norfloxacin and tinidazole in pharmaceutical dosage forms and human plasma

A micellar liquid chromatographic method was developed for the simultaneous analysis of a binary mixture of norfloxacin and tinidazole (NOR and TIN) in dosage forms and human plasma. The analysis was carried out using a Waters Symmetry® C18 column (250 mm x 4.6 mm i.d., 5 µm particle size). The running mobile phase consisting of 0.15 M sodium dodecyl sulphate (SDS), 0.3 % triethylamine (TEA), 5 % n-propanol, the pH was adjusted to 4 by addition of 0.02 M orthophosphoric acid pumped at a flow rate 1.0 mL/min with UV at 275 nm. Calibration curves were linear over the range 1-28 and 1.5-42 µg/mL for NOR and TIN, respectively. The quantification limits were 0.7 and 1.0 µg /mL for NOR and TIN respectively. The proposed method was successfully applied for the simultaneous determination of NOR and TIN in human plasma without prior precipitation of protein. The mean percentage recoveries of bioavailability test in human plasma (n = 3) were 90.31 ± 4.22 and 90.05 ± 1.3 for NOR and TIN, respectively.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Micellar liquid chromatographic method for the simultaneous determination of norfloxacin and tinidazole in pharmaceutical dosage forms and human plasma

A micellar liquid chromatographic method was developed for the simultaneous analysis of a binary mixture of norfloxacin and tinidazole (NOR and TIN) in dosage forms and human plasma. The analysis was carried out using a Waters Symmetry® C18 column (250 mm x 4.6 mm i.d., 5 µm particle size). The running mobile phase consisting of 0.15 M sodium dodecyl sulphate (SDS), 0.3 % triethylamine (TEA), 5 % n-propanol, the pH was adjusted to 4 by addition of 0.02 M orthophosphoric acid pumped at a flow rate 1.0 mL/min with UV at 275 nm. Calibration curves were linear over the range 1-28 and 1.5-42 µg/mL for NOR and TIN, respectively. The quantification limits were 0.7 and 1.0 µg /mL for NOR and TIN respectively. The proposed method was successfully applied for the simultaneous determination of NOR and TIN in human plasma without prior precipitation of protein. The mean percentage recoveries of bioavailability test in human plasma (n = 3) were 90.31 ± 4.22 and 90.05 ± 1.3 for NOR and TIN, respectively.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Caracterización de endemismos mediterráneos en la flora egipcia

The Mediterranean Basin is the world’s second richest hotspot, and one of the most important locations on the planet for endemic taxa. However, there is no available up-to-date list of Mediterranean endemics. Available data are frequently insufficient or outdated. Therefore, this study aimed at delimiting the Mediterranean floristic region in Egypt, screening its Mediterranean endemics, and determining their habitats, life forms, flowering periods, dispersal types and phyto-geographical distribution. From a list of 275 Mediterranean endemic taxa in Egypt compiled from literature, this study reduced it to 57 taxa (including species, subspecies and varieties; 20.7%) belonging to 46 genera and 22 families. Fifteen major habitats harbored Mediterranean endemics in Egypt, with coastal dunes (17 taxa = 29.8%) and non-saline depressions (16 taxa = 28.1%) being the most represented. Moreover, the Mareotis (west) subsector was the richest (46 taxa = 80.7%). The largest number of taxa was recorded in North African sub-region (52 taxa = 91.2%), followed by Eastern (levant) sub-region (36 taxa = 63.2%). Therophytes were the most recorded life form, while ballochory was the most represented dispersal type. In conclusion, it is crucial to shed the light on Mediterranean endemics and provide an up-to-date documented database to help future management plan that support their conservation and sustainable use.La cuenca Mediterránea es el segundo hotspot más rico del mundo y uno de los lugares más importantes del planeta en taxones endémicos. Sin embargo, no existe una lista actualizada de taxones endémicos mediterráneos. Los datos disponibles son frecuentemente insuficientes o están desactualizados. Por tanto, nuestro objetivo fue delimitar la región florística mediterránea en Egipto, seleccionar sus plantas endémicas mediterráneas y determinar sus hábitats, formas de vida, periodos de floración, tipos de dispersión y distribución fitogeográfica. Partiendo de una lista preliminar de 275 taxones endémicos del Mediterráneo presentes en Egipto recopilada de la bibliografía, este estudio redujo ese número a 57 taxones (incluyendo especies, subespecies y variedades; 20.7%) pertenecientes a 46 géneros y 22 familias. Las plantas endémicas mediterráneas de Egipto viven en quince hábitats principales, siendo los más representativos las dunas costeras (17 taxones = 29.8%) y las depresiones no salinas (16 taxones = 28.1%). El subsector Mareotis (al oeste) fue el más rico (46 taxones = 80.7%), mientras que el mayor número de taxones se registró en la subregión del norte de África (52 taxones = 91.2%), seguida de la subregión del este (levante) (36 taxones = 63.2%). Los terófitos fueron la forma vital más registrada y la balocoria el tipo de dispersión más común. En conclusión, es crucial arrojar luz sobre las plantas endémicas del Mediterráneo y proporcionar una base de datos documentada y actualizada que ayude a planificar una gestión futura que promueva su conservación y uso sostenible

Control of hyperphosphatemia in regular hemodialysis (HDx) patients by calcium acetate (CA) versus calcium carbonate (CC). A double blind crossover prospective study

This study included fourty chronic renal failure patients aged 37-83 years (mean 51.3±7) on thrice weekly HDx for 4-144 month (Kt/V >1.2). Acetate dialysate with calcium concentration of 3 mEq/L was used. All phosphate binders were discontinued for one month. Patients were divided in two groups. Group I (20 cases) received CA, while group II (20 cases) received CC in equimolar dose (10 mmol, of either t.i.d.) for one month. Crossover of treatment was done for another month while keeping patients on the same diet.Serum levels of total calcium (Ca), ionized Ca (iCa), phosphorus (P), alkaline phosphates (AP), urea (U), creatinine (Cr), ALT, AST, total proteins (TP) and albumin (Alb) were estimated before, and at the end of each month of CA and CC treatment. Serum Ca and iCa were significantly lower in group I after CA compared to values after CC (p<0.01). Similar results in Ca levels were observed in group II (P<0.05). In group II only serurn P was significantly lower after CA compared to its values after CC (P<0.05). There was no significant difference in AP, U, Cr, ALT, AST, TP and Alb before, and at the end of each month of CA and CC treatment (P>0.05 in all). We excluded 12.5% of cases due to CA intolerance while non of cases had similar intolerance to CC.Conclusion: 1) CA is not very superior to CC in control of hyperphosphataemia. 2) CA can be safely increased without the risk of hypercalcemia. 3) Active Vitamin D and high dialysate Ca can be used to suppress parathyroid activity more safely with CA than with CC. 4) Tolerability to CC is superior

Simultaneous determination of sulpiride and mebeverine by HPLC method using fluorescence detection: application to real human plasma

A new simple, rapid and sensitive reversed-phase liquid chromatographic method was developed and validated for the simultaneous determination of sulpiride (SUL) and mebeverine Hydrochloride (MEB) in the presence of their impurities and degradation products. The separation of these compounds was achieved within 6 min on a 250 mm, 4.6 mm i.d., 5 m particle size Waters®-C18 column using isocractic mobile phase containing a mixture of acetonitrile and 0.01 M dihydrogenphosphate buffer (45:55) at pH = 4.0. The analysis was performed at a flow rate of 1.0 mL/min with fluorescence-detection at excitation 300 nm and emission at 365 nm. The concentration-response relationship was linear over a concentration range of 10- 100 ng/mL for both MEB and SUL with a limit of detection 0.73 ng/mL and 0.85 ng/mL for MEB and SUL respectively. The proposed method was successfully applied for the analysis of both MEB and SUL in bulk with average recoveries of 100.22 ± 0.757% and 99.96 ± 0.625% respectively, and in commercial tablets with average recoveries of 100.04 ± 0.93% and 100.03 ± 0.376% for MEB and SUL respectively. The proposed method was successfully applied to the determination of MEB metabolite (veratic acid) in real plasma simultaneously with SUL. The mean% recoveries (n = 3) for both MEB metabolite (veratic acid) and SUL were 100.36 ± 2.92 and 99.06 ± 2.11 for spiked human plasma respectively. For real human plasma, the mean% recoveries (n = 3) were and respectively